A mobile communication terminal based on Time Division Multiple Access (TDMA) transmits and receives signals to and from a base station by separating a signal transmission interval and a signal reception interval based on a time axis. The mobile communication terminal based on the TDMA suffers from TDMA noise because of power consumption difference between the signal transmission interval and the signal reception interval. That is, the mobile communication terminal consumes more power in the signal transmission interval than the signal reception interval. As a result, the mobile communication terminal is subject to constant frequency noise in accordance with the signal transmission and reception period; that is, the TDMA noise.
Since the TDMA noise deteriorates the communication quality, various conventional methods improve the communication quality by suppressing the TDMA noise. For example, a conventional mobile communication terminal removes the TDMA noise by adding a resistance element to an output path of an audio signal and thus enhances the communication quality. However, the communication quality can be enhanced by adding the resistance element to the output path of the audio signal, whereas a sound volume is decreased. In other situations besides the communication, for example, when an MP3 audio signal is output, Total Harmonic Distortion (THD) increases disadvantageously.